Assignment #2

Assume that g = 10 m/s/s for these problems.  You may need a calculator, though you shouldn't on the quiz.

1.  Consider a ball dropped from rest.  How fast would it be traveling after 2.5 seconds of freefall?

2.  In the problem above, how far would the ball have fallen in this 2.5 seconds?

3.  If you dropped the same ball from the same height on the Moon, would it take a longer or shorter time to hit the surface?

4.  Why are there high altitude directions on boxes of food that has to be boiled?  (Take a look at a box of macaroni and cheese, if possible.)

5.  Thought question.  Knowing what Galileo discovered through his telescope, what do you think was the convincing evidence (for him, or you, if you prefer) that Earth went around the Sun?  In other words, Galileo's telescopic discoveries helped him embrace the Copernican worldview.  Why?

6.  Imagine two stars in space a certain distance apart.  If there distance is tripled (made larger 3 times the original distance), what exactly would happen to the gravitational force between them?

7.  Recall the two short video clips about the inclined planes with the bells.  What was their significance?

8.  Why exactly do two bodies with very different masses fall to the ground with the same acceleration?  (Why would a bowling ball and tennis ball hit the ground at the same time?)

9.  What is "freefall"?  We didn't really discuss this in class, but give it some thought.

10.  Why do astronauts in orbit around the Earth have to exercise so much?


A thought question that does not have an easy answer - really just for you to play with.  It will not be represented on a quiz.  Around the year 1600, virtually no one believed in a heliocentric universe.  By the year 1700, virtually everyone did.  What could have possibly caused such a dramatic change in public opinion?